YAML Validator

Validate YAML syntax and pinpoint errors by line and column for Kubernetes, Docker Compose, and CI/CD configs.

For this tool, processing runs locally in your browser and data is not sent to the server.

YAML Validator is a free online tool that checks YAML syntax and helps you quickly find errors in configs, Kubernetes manifests, Docker Compose files, GitHub Actions workflows, and GitLab CI pipelines. It shows a validity status, error message, line, column, and a context snippet. The tool runs in your browser and does not send data to the server.

What it does

Output

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How to use

Paste a YAML config, Kubernetes manifest, Docker Compose file, GitHub Actions workflow, or other YAML fragment.
Choose a validation mode: standard YAML or a relaxed mode for fragments.
Check the status: YAML valid or YAML contains an error.
If there is an error, read the message, line, column, and the context snippet around the problem.

More about this tool

YAML Validator checks YAML syntax and helps you quickly find errors in configs, Kubernetes manifests, Docker Compose files, GitHub Actions workflows, GitLab CI pipelines, and other dev settings. The tool shows a validity status, error message, line, column, and a snippet around the problem.

For valid YAML, the service shows basic structure statistics: lines, keys, arrays, maximum depth, root type, and document size. It can also warn about tabs in indentation and trailing spaces. The validator checks YAML syntax but does not replace schema validation for Kubernetes, Docker Compose, or CI/CD.

All processing is done locally in the browser. Your data is not sent to the server.

Runs in the browser
Data is not sent to the server
Validates YAML syntax
Shows validity status
Pinpoints error line and column
Warns about tabs and trailing spaces
Useful for Kubernetes, Docker Compose, and CI/CD files
No registration required

Frequently Asked Questions

What does the YAML Validator do?

It checks whether YAML can be read by a parser and shows the status: YAML valid or YAML contains a syntax error.

Does the validator show the location of the error?

Yes. Where the parser returns a position, the tool shows the error message, line, column, and a context snippet around the problem.

Why does YAML often break because of indentation?

In YAML, indentation defines data nesting. An extra space, wrong nesting level, or a tab instead of spaces can corrupt the structure.

Can I use tabs in YAML?

Spaces are recommended for YAML indentation. The tool warns about tabs at the beginning of lines.

Does the tool validate Kubernetes manifests?

The tool validates YAML syntax but not Kubernetes schema. The YAML may be syntactically valid but still incorrect for Kubernetes.

Is the tool suitable for GitHub Actions and GitLab CI?

Yes, for basic YAML syntax checking. Workflow or pipeline correctness must be validated with platform-specific validators.

How is the YAML Validator different from the YAML Formatter?

The validator shows whether there is a syntax error and where it is. The formatter brings valid YAML to a clean form with chosen indentation.

Does the validator fix YAML automatically?

No. The tool shows the error and hints but does not automatically modify the config, to avoid corrupting the structure.

Is my data sent to the server?

No. YAML is processed locally in the browser and is not sent to the server.

Do I need to register?

No. The tool works immediately without registration.

How to use

Paste a YAML config, Kubernetes manifest, Docker Compose file, GitHub Actions workflow, or other YAML fragment.

Choose a validation mode: standard YAML or a relaxed mode for fragments.

Check the status: YAML valid or YAML contains an error.

If there is an error, read the message, line, column, and the context snippet around the problem.

More about this tool

All processing is done locally in the browser. Your data is not sent to the server.

Runs in the browser
Data is not sent to the server
Validates YAML syntax
Shows validity status
Pinpoints error line and column
Warns about tabs and trailing spaces
Useful for Kubernetes, Docker Compose, and CI/CD files
No registration required

Frequently Asked Questions

What does the YAML Validator do?

It checks whether YAML can be read by a parser and shows the status: YAML valid or YAML contains a syntax error.

Does the validator show the location of the error?

Yes. Where the parser returns a position, the tool shows the error message, line, column, and a context snippet around the problem.

Why does YAML often break because of indentation?

In YAML, indentation defines data nesting. An extra space, wrong nesting level, or a tab instead of spaces can corrupt the structure.

Can I use tabs in YAML?

Spaces are recommended for YAML indentation. The tool warns about tabs at the beginning of lines.

Does the tool validate Kubernetes manifests?

The tool validates YAML syntax but not Kubernetes schema. The YAML may be syntactically valid but still incorrect for Kubernetes.

Is the tool suitable for GitHub Actions and GitLab CI?

Yes, for basic YAML syntax checking. Workflow or pipeline correctness must be validated with platform-specific validators.

How is the YAML Validator different from the YAML Formatter?

The validator shows whether there is a syntax error and where it is. The formatter brings valid YAML to a clean form with chosen indentation.

Does the validator fix YAML automatically?

No. The tool shows the error and hints but does not automatically modify the config, to avoid corrupting the structure.

Is my data sent to the server?

No. YAML is processed locally in the browser and is not sent to the server.

Do I need to register?

No. The tool works immediately without registration.